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OPHTHALMOLOGY CLINIC MedicineToday PEER REVIEWED Medical and surgical treatment of recurrent corneal erosions PATHOPHYSIOLOGY Topical lubrication is the mainstay of medical treatment for recurrent corneal erosion, with surgery being reserved for those patients in whom medications fail to control symptoms or are not tolerated. MedicineToday 2012; 13(8): 71-73 R ecurrent corneal erosion (RCE) syndrome is a relatively common and painful eye condition characterised by recurrent sloughing off of the corneal epithelium.1 It is episodic in nature and typically occurs after corneal injury, generally in patients with an underlying corneal dystrophy. The first symptom of an episode is usually pain upon awakening or that causes the patient to wake up. RCE syndrome is a not uncommon presentation in primary care medicine. Although the condition is not immediately sightthreatening, patients are often quite distressed and bewildered on presentation because of the combination of severe pain and the unexpected nature of the problem. A history of eye pain upon awakening and opening the eyes or that awakens the patient is highly suggestive of RCE syndrome.1 Fortunately, the condition can often be controlled with the long-term use of topical lubrication or other medication. In some cases, however, surgical intervention may be required.2 Review by an ophthalmologist is important to establish the diagnosis of the condition and exclude any other sight-threatening pathology. Dr Singh is an Ophthalmic Surgeon in private practice in Newcastle and Lake Macquarie, and a VMO at John Hunter Hospital, Newcastle. Professor Sutton is an Ophthalmic Surgeon in Chatswood, and1Chair of Cornea andPM Refractive Copyright _Layout 17/01/12 1:43 Page 4 The cornea is composed of five layers. These are, from anterior to posterior, the corneal epithelium, Bowman’s membrane, corneal stroma, Descemet’s membrane and corneal endothelium (Figure 1). The basal cells of the corneal epithelium are anchored to the underlying Bowman’s membrane and stroma through an adhesion complex formed by attachment structures (hemidesmosomes) on these cells and the secretion by these cells of the basement membrane. Recurrent corneal erosions are thought to be caused by a disruption to this adhesion complex. This results in loose adhesion between the epithelium and underlying corneal layers, leaving the epithelium prone to erosion and potential exposure of the densely populated sensory nerve endings of the corneal subepithelial nerve plexus. The most common causes of disruption to the adhesion complex are previous corneal abrasions and corneal dystrophies. Patients with corneal erosion caused by injury often also have an underlying corneal dystrophy (Figure 2). By far the Bowman’s membrane Epithelium Stroma Descemet’s membrane Cornea Endothelium © CHRIS WIKOFF, 2012 RAVI SINGH FRANZCO GERARD SUTTON FRANZCO Figure 1. The five layers of the cornea. Disrupted attachment of the epithelium to the underlying corneal layers accounts for the recurrent epithelial erosion seen in RCE syndrome. Surgery, Sydney Medical School, The University of Sydney, NSW. MedicineToday ❘ August 2012, Volume 13, Number 8 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2012. 71 OPHTHALMOLOGY CLINIC CONTINUED most common abrasive injuries are those from human fingernails and vegetable material such as tree leaves and branches. The most common corneal dystrophy is anterior basement membrane dystrophy. RCE syndrome is usually unilateral but corneal dystrophies are usually bilateral. The sudden pain often felt in an episode of RCE syndrome on awakening or during sleep occurs because the lid and cornea may have adhered overnight and movement of the lid on waking or of the eye during rapid eye movement sleep causes tearing of the loosened corneal epithelium.2 CLINICAL FEATURES Figures 3a and b. a (left). Inferior corneal epithelial erosion. b (right). Fluoroscein staining and cobalt blue light highlighting the corneal erosion. DIAGNOSIS The diagnosis of RCE syndrome is made on clinical history and physical examination. Episodes of eye pain or grittiness upon awaking or that wake the patient during the early morning hours are highly suspicious for the condition. A concomitant history of ipsilateral traumatic corneal abrasion, even months earlier, is highly suggestive of recurrent corneal erosion. Examination of the eye using fluorescein staining at the time of the attack may reveal signs of a corneal erosion (Figures 3a and b). Milder attacks may not be obvious without a careful slit lamp examination. The corneal epithelium has a rapid and extensive replicative capacity and, especially in milder cases of the disease, the signs may have completely resolved by the time of examination. In patients with an underlying corneal dystrophy, slit lamp examination may show signs of this in both the eye with corneal erosion and the fellow eye. During an acute attack of RCE syndrome, the corneal epithelium is eroded and the underlying sensory nerves are exposed. Symptomatically, there is variable discomfort, ranging from foreign body sensation to extreme pain, in association with lacrimation and photophobia. The symptoms can last from minutes MANAGEMENT to hours. Managing RCE syndrome involves iniThe debilitating aspect of this disease tially facilitating corneal healing (acute is its recurrent nature, with the threat and management) followed by preventing fear of a painful attack being anxiety pro- further attacks. voking for patients. Patients will often describe techniques Acute management to avoid the erosion, such as learning to The acute management of corneal keep their eyes closed when they wake erosions comprises controlling pain, up and gently rubbing the eyelids to pre- encouraging corneal re-epithelialisation vent a rapid cornealCopyright epithelial_Layout tear before and1:43 minimising 1 17/01/12 PM Page 4the risks of infection. opening the eyes. The initial management depends on 72 MedicineToday ❘ the severity of the symptoms. Any loose epithelium should be debrided as this generally impedes healing (see below under ‘Surgical treatment’). Severe pain may be alleviated with the use of a bandage soft contact lens, which protects the ulcerated corneal surface from friction during blinking and also from external sources of injury. Oral analgesia is often required, especially if a bandage contact lens is not used. A topical antibiotic such as chloramphenicol eye ointment should be prescribed to protect against infection, and this will also act as a lubricant. A medium duration-acting cycloplegic such as homatropine may be required to relieve ciliary muscle spasm. Prevention of attacks Medical treatment The vast majority of recurrences of corneal erosions can be prevented with medications. A detailed Cochrane review is available on the medical treatment of recurrent erosions of the cornea .2 Topical lubrication, especially with paraffin-based ointment at night before sleeping, is the mainstay of medical treatment for preventing recurrent erosions.1-7 This creates a barrier between the eyelid and cornea and is generally effective in preventing further attacks of corneal erosions in most patients. It does, however, need to be continued for six to 12 months to allow adequate re-adhesion of the corneal epithelium to the underlying August 2012, Volume 13, Number 8 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2012. FIGURE 2: © SCIENCE PHOTO LIBRARY/GETTY IMAGES Figure 2. Patient with anterior basement membrane dystrophy. underlying Bowman’s membrane that allows new epithelium to regenerate and anchor more securely to the underlying layers. There is a small risk of corneal haze with this treatment. Anterior stromal puncture. Micropuncture of the anterior part of the stroma at the site of recurrent erosion using a 23 gauge needle or Nd:YAG laser can also be effective in creating an adhesion complex stimulated by scar formation.1,7 This procedure is best used for erosions off the visual axis to avoid visually symptomatic scars. Diamond burr polishing. Diamond burr polishing of the bed of the erosion after epithelial debridement is also effective at inducing epithelial adhesion and has the advantages of being inexpensive and available in the offices of most ophthalmologists. However, it can rarely cause corneal haze.5 CONCLUSION In some patients, medical treatment fails • Phototherapeutic keratectomy (PTK). to control the symptoms of RCE syndrome In PTK, the excimer laser, the laser or is not tolerated. This often leads to commonly used for laser surgery of significant worry and anxiety for patients the cornea (laser-assisted in-situ because they become fearful of the pain keratomileusis [LASIK]), is used to that may awake them or occur upon debride the corneal Bowman’s awaking. Surgical therapies can be used membrane after the epithelium has with a high degree of success in such cases. been removed. The ablated Bowman’s There is no one treatment that is beneficial membrane facilitates more secure for all patients so the choice will depend attachment of the corneal epithelium on factors such as availability of treatment to the underlying corneal layers as and the severity and site of the corneal the corneal epithelium grows back erosion. Although effective, the surgical onto the cornea. This treatment, treatments may require repeating for furavailable in almost every major ther recurrences. city, is effective (74 to 100%) in The following surgical treatments are preventing recurrence of symptoms, available. although there may be recurrences in a minority of patients and compli • Epithelial debridement. Debridement of the epithelium with a cotton tip can cations such as corneal haze and be an effective and readily available infection are possible.6 There is the treatment. The treatment effect can potential, however, for PTK to induce be optimised by using a solution of a hyperopic shift in the patient’s 20% alcohol to loosen the epithelium refraction, which may necessitate a from the underlying cornea.4 The change of glasses or contact lenses result is a very clean dissection plane further laser4surgery in some Copyright _Layout 1 17/01/12 or 1:43 PM Page between the corneal epithelium and instances to correct the hyperopia. REFERENCES layers. Any signs of underlying dry eye or uncontrolled blepharitis should be treated with topical lubrication and lid hygiene measures (hot compresses and eyelid scrubbing), with additional oral doxycycline in more severe cases. If topical lubrication does not prevent further attacks of RCE syndrome, medical treatment with a topical corticosteroid (such as flurometholone 0.1%) and oral doxycycline (100 mg daily) may be needed. This therapy has been reported to be beneficial for treating recurrent attacks and preventing further attacks.2,3 The treatment period is usually for at least one month. This treatment has the advantage of being noninvasive and effective (83% of patients were free of symptoms at six months and 73% at 12 months).3 It can also benefit patients who have recurrences despite surgical intervention. Its disadvantage is the potential for side effects. Surgical treatment for recurrences despite medical treatment • • RCE syndrome is a painful eye condition that is usually related to trauma. Its typical presentation is ocular pain and foreign body sensation experienced on opening the eye upon normal awakening or occurring during sleep and awakening the patient. The history will usually be enough to make the diagnosis, although a slit lamp examination is mandatory. Patients who experience corneal erosions are initially anxious and bewildered by their onset and when they recur become distressed at the thought of continuing attacks causing pain and interrupting normal sleep patterns. The symptoms can often be controlled with ocular lubricants or other medication, and surgery if these fail. RCE syndrome may remain a lifelong problem for patients due to its recurrent nature. This may be especially so in patients with corneal dystrophies, who have an underlying genetic abnormality predisposing them to corneal erosion. MT 1. ewald m, Hammersmith Km. review of diagnosis and management of recurrent erosion syndrome. Curr opin ophthalmol 2009; 20: 287-291. 2. Watson sl, barker NH. Interventions for recurrent corneal erosions. Cochrane Database syst rev 2007; (4): CD001861. 3. Wang l, tsang H, Coroneo m. treatment of recurrent corneal erosion syndrome using the combination of oral doxycycline and topical corticosteroid. Clin experiment ophthalmol 2008; 36: 8-12. 4. singh rP, raj D, Pherwani A, et al. Alcohol delamination of the corneal epithelium for recalcitrant recurrent corneal erosion syndrome: a prospective study of efficacy and safety. br J ophthalmol 2007; 91: 908-911. 5. soong HK, Farjo Q, meyer rF, sugar A. Diamond burr superficial keratectomy for recurrent corneal erosions. br J ophthalmol 2002; 86: 296-298. 6. baryla J, Pan YI, Hodge Wg. long-term efficacy of phototherapeutic keratectomy on recurrent corneal erosion syndrome. Cornea 2006; 25: 1150-1152. 7. Das s, seitz b. recurrent corneal erosion syndrome. surv ophthalmol 2008; 53: 3-15. COMPETING INTERESTS: None. MedicineToday ❘ August 2012, Volume 13, Number 8 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2012. 73